Concerned about DN

My family live a few hundred miles away. dm 82 called today to tell me that she'd had Db and nephews over at the weekend and had asked them to help her weed the front of her house (no grass just a arrow border) ds-in law went of the shops, Db was on computer dn's were on various gadgets. Dn1 13 said her didn't want to and his df sand him started arguing. Dm told them to get inside next thing they are rolling on the floor fighting! Db isn't a big fella but his son is 13! Dm steps in and told them to stop Db walked out, dn broke down in tears - in shock dm said he wasn't hurt at all. I went ballistic on the phone when dm told me.How dare Db lose his temper with his son - child abuse is what I called it. Poor dn has enough issues (hair lip, cleft pallet, food issues).dm blamed ds-in law for putting dn under pressure as she works too long hours Db turned up all remorseful seemingly, and they went off home. Poor dm having to witness all that. But poor dn... I don't know if his has happens before jeez I feel awful... And angry too and sad. Dm said there is so much about my late df I didn't know and he had given Db a hiding or two... But there is no way on earth I ever witnessed that. Db was a little angry turd most of his life. Currently hate my family,